Cancer has been shown in many cases to result from mutations of normal gene sequences. In terms of the total number of humans affected, the most serious hereditary cancer risk is associated with breast cancer. Among women who have a blood relative with the disease the risk of developing breast cancer is close to 1 in 5. AndCare proposes to develop a rapid new method for the quantitative electrochemical detection of altered nucleic acid sequences (gene sequences) in complex mixtures. The heart of the method is capture of a nucleic acid fragment by hybridization with a complementary sequence at the surface of a biosensor, followed by electrochemical detection of the captured target. A sample with altered or mutated DNA will give a reduced current as a result of decreased capture or detection efficacy. AndCare will demonstrate the ability of its differential electrochemical detection system to rapidly detect mutations in a major breast and ovarian cancer susceptibility gene (BRCA1). the system avoids the use of electrophoresis and radioisotopes. Dr. Henkens and his staff have pioneered the use of screen-printed, disposable, amperometric sensors using colloidal gold electrodes for use with electrochemical monitors. This technology is the platform that will be used in this project. PROPOSED COMMERCIAL APPLICATION: We believe that our differential electrochemical gene-probe detection method will provide an innovative new technology for detection of gene alterations. The new methods are also applicable to research areas of the Division of Cancer Biology concerned with biological carcinogenicity. We envision better (faster, simpler, cheaper) determination of differences in normal nucleic acid sequences and in identification of alterations that may lead to cancer and other pathological conditions.